An old readily available anti-malaria drug has shown promise in treating cancer in a pre-clinical trial, and the drug could be repurposed as a cancer therapy, new research has found.
Atovaquone is a chemical compound which has been used in anti-malarial medication since 2000. It is also sold by GSK drug company under the name Mepron to treat or prevent certain types of pneumonia caused by a fungal infection. This off-patent malaria drug is cheaply available from generic manufacturers.
The Cancer Research UK researchers revealed on Monday that Atovaquone has potential to treat a broad range of cancers, including lung, bowel, brain, and head and neck cancer.
In pre-clinical trials in mice, the researchers obtained promising results showing the drug’s capability to stop tumors from having a low-oxygen environment during radiotherapy. Cancer cells with low oxygen levels or hypoxia are more difficult to treat with radiotherapy and are more susceptible to spread (metastasis) to other body organs. Atovaquone reverses the low-oxygen levels in tumour cells, as a result the fully-oxygenated tumours get more easily destroyed by radiotherapy.
“The types of cancer that tend to have oxygen deprived regions are often more difficult to treat – such as lung, bowel, brain and head and neck cancer,” Emma Smith, Cancer Research UK’s Science Information Manager, said in a statement.
“Clinical trials will tell us whether this drug could help improve treatment options for patients with these types of tumour,” she noted.
According to the cancer research findings, this malaria medication elevated oxygen levels in tumor cells in mice, making them easier to destroy during radiotherapy. The promising results prompted the researchers to start testing the effects of the drug in clinical trials involving human models.
“This is an exciting result. We have now started a clinical trial in Oxford to see if we can show the same results in cancer patients,” said study lead author Gillies McKenna from Cancer Research UK Radiation Research Centre in Oxford.
“We hope that this existing low cost drug will mean that resistant tumours can be re-sensitised to radiotherapy. And we’re using a drug that we already know is safe,” McKenna said.
The idea of repurposing well-established drugs to fight cancer is gaining popularity as scientists realize that existing medication may complement other therapies. Moreover, such older drugs are no longer patented means they are cheap and readily available.